Adjustable Moment of Inertia Bat

ABSTRACT

An adjustable moment of inertia ball bat has a hollow outer ball bat shell defining an interior cavity having an open distal end. A central shaft is disposed in the interior cavity and a weight is disposed on the central shaft. The central shaft passes through and operatively engages the weight. An interior support secures an inner end of the central shaft and a bat end cap is adapted to be fitted into the open distal end of the ball bat shell. The weight moves in the ball bat shell on the central shaft to operatively adjust a moment of inertia of the ball bat.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to ball sports bats, more particularly to providing ball sports bats with an adjustable Moment of Inertia (MOI), and specifically embodiments of adjustable MOI game play bats.

2. Description of the Prior Art

A high percentage of non-professional baseball and softball players use non-wooden bats, such as those constructed of aluminum or resin composites. A number of references propose various methods of adding weights to ball bats and/or providing an adjustable weight in a practice bat or the like. For example, Dribble, U.S. Pat. No. 64,081 discloses a hollow club, with weights mounted on a central threaded rod, where the weights can be adjusted to adjust the balance of the club. Similarly, Brock, U.S. Pat. No. 7,056,240 discloses a training bat having a weight mounted on a central threaded support, wherein the position of the weight can be adjusted by rotation of the support to affect balance of the bat. Chang, U.S. Pat. No. 6,767,299 discloses a wooden bat having a central threaded core, into which a weight is threaded to adjust the center of gravity of the bat, which would not be legal for game play in baseball. Thus, the prior art fails to disclose an adjustable MOI bat usable for game play.

SUMMARY

The present invention is directed to systems and methods, which provide an adjustable MOI game play ball bat having a hollow outer ball bat shell that defines an interior cavity with an open distal end, and that further includes a central shaft disposed in the interior cavity. A weight is disposed on the central shaft and the central shaft passes through and operatively engages the weight. An interior support secures an inner end of the central shaft. A bat end cap is adapted to be fitted into the open distal end of the ball bat shell, and the weight is moved in the ball bat shell on the central shaft to operatively adjust a MOI of the game play bat.

Hence, it is an object of the present invention to provide a ball sport bat, such as a baseball bat, softball bat, or cricket bat that, while being as light as possible and meeting established testing standards, provides a degree of flexibility to move weight along the length of the barrel of the bat, such that this movable weight allows a user to adjust the MOI of the bat, thereby giving the player an ability to customize the MOI of the bat to his or her personal tastes.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter, which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form part of the specification in which like numerals designate like parts, illustrate embodiments of the present invention and together with the description, serve to explain the principles of the invention. In the drawings:

FIG. 1 is a fragmented view of the present adjustable MOI bat, according to one embodiment;

FIG. 2 is an exploded view of an insert such as may be used in the adjustable MOI bat of FIG. 1, according to one embodiment; and

FIG. 3 is a fragmented view of an adjustable MOI bat, according to another embodiment.

DETAILED DESCRIPTION

The present bat is an adjustable MOI bat, which is preferably fully functional for game play and is preferably capable of being certified for such by the appropriate governing bodies. Various embodiments of the present bat may be used in a ball game, such as baseball, softball, cricket, or the like, at all levels of play. In accordance with various embodiments, the present adjustable MOI game play ball bat has a hollow outer ball bat shell that defines an interior cavity, which in turn includes an open distal end. The adjustable MOI features of the bat may include a central shaft disposed in this interior cavity. At least one weight may be operatively disposed on the central shaft. This central shaft may pass through and operatively engage the weight according to various embodiments. An interior support may retain an inner end of the central shaft. A bat end cap may be adapted to be fitted into the open distal end of the ball bat shell, through which adjustment of the position of the weight may be carried out in accordance with various embodiments. Hence, the weight may be moved in the ball bat shell, on the central shaft to operatively adjust an MOI of the game play bat.

In accordance with various embodiments it may be desirable to thread an interior of an insert tube and make corresponding threads in one or more moveable weights inside this central tube. An end cap with a rotating element may allow a user to move the weight up and down the barrel of the bat. The bottom and/or top of the central tube may be secured to the barrel of the bat with shock absorbing material that reduces vibration and shock to a batter's hands. In accordance with such embodiments, the weight is moved by an implement or tool applied at the end-cap as a means to adjust the weight along the length of the barrel of the bat. The central insert with weight may be fitted to a bat end-cap and then press fitted into the bat as a single unit. The end cap may define a mechanism that enables movement of the weight.

Thus, with attention directed to the drawings, FIG. 1, a fragmented view of the present adjustable MOI bat according to one embodiment, shows adjustable MOI game play bat 100. Adjustable MOI insert 102 is provided for game play ball bat 100. In accordance with the illustrated embodiment of adjustable MOI game play ball bat 100, hollow outer ball bat shell 104 defines interior cavity 106 having open distal end 108. Bat shell 104 may be a more-or-less conventional game play ball bat shell made of aluminum, a composite material, or the like.

FIG. 2 is an exploded view of insert 102, such as may be used in adjustable MOI bat 100 of FIG. 1, according to one embodiment, such as to provide MOI adjustment. Hence, with attention directed variously to FIGS. 1 and 2, insert 102 may include cylindrical tubular housing 110 defining internal threads 112. Housing 110 may be made of a resilient material, such as plastic (i.e. polyvinyl chloride, or the like) and housing 110 may be secured in interior cavity 106 of bat 100 by vibration dampening material 114, or the like. By way of example, such dampening material may include a resilient material such as plastic, rubber, silicone, or the like, and may be disposed about an interior end of the cylindrical tubular housing. Externally threaded weight 116, which may be at least partially cylindrical, is disposed in cylindrical tubular housing 110. External threads 118 of weight 116 operatively engage internal threads 112 of cylindrical tubular housing 110, as may be best seen in FIG. 1. Weight 116 may be made of one or more materials, such as lead, steel, titanium, aluminum, tungsten, and/or the like. Central shaft 120 passes through and longitudinally, slideably engages weight 116, for rotation of weight 116. That is, such that weight 116 may slide along central shaft 120, yet be rotated by central shaft 120. By way of example, such as illustrated in FIGS. 1 and 2, central shaft 120 may be square in cross-section, and weight 116 may define central, square keyway 202 through its center (see FIG. 2). Thus, central shaft 120 may pass tightly through keyway 202, yet longitudinally slideably engaging weight 116 for rotation of weight 116 in housing 110, cooperatively on threads 112 and 118 for MOI adjustment.

Interior support 122 may be in the form of a plug or cap and may be disposed in interior end 124 of cylindrical tubular housing 110. In accordance with various embodiments, interior support 122 may be fixed in or on housing interior end 124, and interior support 122 may rotatably secure inner end 126 of central shaft 120, such as through interior support orifice 204 (see FIG. 2), using clip 128. In accordance with other possible embodiments, an embodiment of interior support 122 fixedly secures inner end 126 of central shaft 120 such as in an embodiment of interior support orifice 204, which defines a square keyway, again using clip 128. In such an embodiment interior support 122 may rotate with respect to housing 110, such as within interior end 124 of housing 110. As a further alternative, interior support 126 may in accordance with various embodiments engage the interior of bat shell 104, and may frictionally engage bat shell 104.

In accordance with the illustrated embodiments of FIGS. 1 and 2, bat end cap 130 is adapted to be fitted into outer end 132 of cylindrical tubular housing 110 and concurrently into open end 108 of a hollow ball play bat shell 104. Bat end cap 130 and/or open distal end 108 of ball bat shell 104 may be sized such that bat end cap 130 may be press-fitted into ball bat shell open distal end 108, thereby securing insert 102 in the bat in accordance with various embodiments. Adjustment plug 134 may be rotatably disposed in central orifice 206 (see FIG. 2) defined in bat end cap 130 and may be fixed, and/or otherwise mate, to outer end 136 of central shaft 120. Thereby, rotation of plug 134 rotates central shaft 120, rotating externally threaded weight 116 in cylindrical tubular housing 110, on the internal threads 112, to move weight 116 in housing 110. To this end, plug 134 may define external slot 138 in its outer surface to receive an implement such as a coin, medallion or the like, to rotate plug 134. For example, in accordance with various embodiments plug 134 may define slot 134, with the illustrated curved bottom, thereby adapted to receive the edge of a coin to rotate plug 134. Alternatively or additionally, plug 134 may define an external socket in its outer surface, in place of slot 138, to receive a tool, such as a screw driver, allen wrench, TORX® driver, to rotate plug 134. Further to this end, plug may define, internal socket 208 (see FIG. 2) to mate with outer end 136 of central shaft 120. As a further alternative, plug 134 may be replaced with a head defined by central shaft 120. This head may define the aforementioned external slot and/or socket, which may be used to rotate central shaft 120 to adjust the MOI of bat 100.

Thus, in accordance with various embodiments of operation, the MOI of game play ball bat 100 illustrated in FIGS. 1 and 2 may be adjusted by rotating central shaft 120 in ball bat insert 102, thereby rotating externally threaded weight 116 in cylindrical tubular housing 110 of insert 102 on internal threads 112 defined in an inner wall of housing 110. This moves weight 116 in housing 110 and in ball bat shell 104, along central shaft 120 to operatively adjust an MOI of the bat. As described above, rotation of central shaft 120 may be carried out using an implement such as a coin, or a tool such as an allen wrench or TORX® driver, indexing with plug 134, disposed in bat end cap 130 and mated with outer end 136 of central shaft 120. Hence, in accordance, with various embodiments such adjustments may be made during the course of game play, such as between at-bats, or even during an at-bat.

FIG. 3 is a fragmented view of adjustable MOI bat 300, another adjustable MOI bat embodiment. Adjustable MOI game play bat embodiment 300 shown in FIG. 3 employs alternative adjustable MOI insert 302. Adjustable MOI game play ball bat 300 also includes a hollow outer ball bat shell (304) that defines an interior cavity (306) having an open distal end (308). Bat shell 304 may also be a more-or-less conventional game play ball bat shell made of aluminum, a composite material, or the like.

Insert 302 may include weight 316, disposed on tubular central shaft 320. Again, weight 316 may be made of one or more materials, such as lead, steel, titanium, aluminum, tungsten, and/or the like. Central shaft 320 passes through and longitudinally, slideably engages weight 316, for maintaining position of weight 316. That is, such that weight 316 may slide along central shaft 320, yet be held in selected positions at indents 324 defined in central shaft 320 for MOI adjustment.

Interior support 326 is disposed at interior end of central shaft 320 and in accordance with various embodiments engages the interior of bat shell 304. In accordance with various embodiments, interior support 326 may be fixed on central shaft 320 and frictionally engage bat shell 304 to possibly assist in maintaining central shaft 320 in position. Insert 302 may be supported in the interior cavity by vibration dampening material (not shown), such as dampening material disposed about interior support 326, for example between bat shell 304 and inner support 326.

In accordance with illustrated embodiment 300 of FIG. 3, bat end cap 330 is adapted to be fitted onto an outer end of central shaft 320 and into open end 308 of hollow ball play bat shell 304. Bat end cap 330 and/or open distal end 308 of ball bat shell 304 may be sized such that bat end cap 330 may be to be press-fitted into ball bat shell open distal end 308, thereby securing insert 302 in the bat and against rotation relative to bat shell 304, in accordance with various embodiments. An adjustment tool opening may be defined in bat end cap 330 for receiving a tool, such as an elongated push rod, allen wrench, TORX® driver, slotted screwdriver, Phillips screwdriver, or the like to engage weight 316 and disengage weight 316 from one indent 324 for movement along central shaft 320 to another indent 324 position, to thereby adjust the MOI of bat 300.

In accordance with embodiment 300, as illustrated in FIG. 3, weight 316 may be slideably mounted on central shaft 320, and, by way of example, indexed to slot 340 by pin 342 and retained in place by pin 344 indexing with one of indents 324, under tension from spring 346, imparted via sleeve 348.

In accordance with various embodiments of ball game play bat 300, disengagement of weight 316 from one indent 324 and movement along central shaft 320 to another indent 324, to thereby adjust the MOI of bat 300 under tension from spring 346, may be made during the course of game play, such as between at-bats, or even during an at-bat.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. 

What is claimed is:
 1. An adjustable moment of inertia ball bat comprising: a hollow outer ball bat shell defining an interior cavity having an open distal end; a central shaft disposed in said interior cavity; a weight disposed on said central shaft, said central shaft, passing through and operatively engaging said weight; an interior support securing an inner end of said central shaft; a bat end cap adapted to be fitted into said open distal end of said ball bat shell; and means for moving said weight in said ball bat shell on said central shaft to operatively adjust a moment of inertia of said ball bat.
 2. An adjustable moment of inertia insert for a ball bat, said insert comprising: a cylindrical tubular housing defining internal threads; an externally threaded, at least partially cylindrical weight disposed in said cylindrical tubular housing, external threads of said weight operatively engaging said internal threads of said cylindrical tubular housing; a central shaft passing through and longitudinally slideably, rotationally engaging said weight; an interior support disposed in an interior end of said cylindrical tubular housing, said interior support rotatably securing an inner end of said central shaft; and a bat end cap adapted to be fitted into an outer end of said cylindrical tubular housing and a open distal end of a hollow ball play bat.
 3. The adjustable moment of inertia insert of claim 2, wherein rotation of said central shaft, rotates said externally threaded weight in said cylindrical tubular housing on said internal threads to move said weight in said housing and in a ball bat wherein said insert is disposed to operatively adjust a moment of inertia of said ball bat.
 4. The adjustable moment of inertia insert of claim 2, wherein said cylindrical tubular housing is made of a resilient material.
 5. The adjustable moment of inertia insert of claim 4, wherein said resilient material is polyvinyl chloride plastic.
 6. The adjustable moment of inertia insert of claim 2, wherein said weight is comprised of one or more of lead, steel, titanium, aluminum and tungsten.
 7. The adjustable moment of inertia insert of claim 2, wherein said central shaft is a shaft that is square in cross-section and said weight defines a square keyway through its center, said central shaft passing through said keyway, longitudinally slideably engaging said weight.
 8. The adjustable moment of inertia insert of claim 2, wherein said interior support secures said inner end of said central shaft and said interior support rotates with respect to said housing.
 9. The adjustable moment of inertia insert of claim 2, wherein said bat end cap is adapted to be press fitted into said open distal end of said ball bat.
 10. An adjustable moment of inertia game play ball bat comprising: a hollow outer ball bat shell defining an interior cavity having an open distal end; a cylindrical tubular housing defining internal threads disposed in said interior cavity; an externally threaded cylindrical weight disposed in said cylindrical tubular housing, external threads of said cylindrical weight operatively engaging, said internal threads of said cylindrical tubular housing; a central shaft passing through and longitudinally slideably and rotationally engaging said cylindrical weight; an interior support disposed in an interior end of said cylindrical tubular housing, said interior support rotatably securing an inner end of said central shaft; and a bat end cap adapted to be fitted into an outer end of said cylindrical tubular housing and said open distal end of said ball bat shell.
 11. The game play bat of claim 10, wherein rotation of said central shaft rotates said externally threaded weight in said cylindrical tubular housing on said internal threads to move said weight in said housing and in said ball bat shell to operatively adjust a moment of inertia of said game play bat.
 12. The game play bat of claim 10, wherein said bat shell is made of aluminum or a composite material.
 13. The game play bat of claim 10, wherein said cylindrical tubular housing is made of a resilient material.
 14. The game play ball bat of claim 13, wherein said resilient material is polyvinyl chloride plastic.
 15. The game play ball bat of claim 10, wherein said cylindrical tubular housing is secured in said interior cavity by vibration dampening material.
 16. The game play ball bat of claim 15, wherein said dampening material is disposed about said interior end of said cylindrical tubular housing.
 17. The game play bat of claim 10, wherein said weight is comprised of one or more of lead, steel, titanium, aluminum, and tungsten.
 18. The game play bat of claim 10, wherein said central shaft is shaft that is square in cross-section and said cylindrical weight defines a square keyway through its center, said central shaft passing through said keyway, longitudinally slideably, rotationally engaging said cylindrical weight.
 19. The game play bat of claim 10, wherein said interior support secures said inner end of said central shaft and said interior support rotates with respect to said housing.
 20. The game play bat of claim 10, wherein said bat end cap is adapted to be press fitted into said open distal end of said ball bat shell.
 21. A method comprising: rotating a weight of a game play ball bat insert, moving said weight along a central shaft to a second position, thereby operatively adjusting a moment of inertia of said game play bat.
 22. A method comprising: rotating a central shaft of a game play ball bat insert, thereby rotating an externally threaded weight, in a cylindrical tubular housing of said insert on internal threads defined in an inner wall of said housing, moving said weight in said housing and in said ball bat shell, along said central shaft to operatively adjust a moment of inertia of said game play bat. 